What can cause a DIGI ONE SP to lose connection every weekish?

We have a machine that is causing the DIGIs to lose connection every few days to a couple weeks. We have eight other machines setup the exact same everywhere from the machine to the cisco switch. This machine is the only one displaying the problem. We put the DIGI on a separate power line thinking that was the problem but it has not resolved the issue. The settings on everything are the exact same on all the machines. I have switched the DIGI out five times with all having the same problems after a random amount of days. One lasted only three days and another lasted close to two weeks. Are there any fail-safes I could set so that the connection does not stop working?

Sometimes if we take out the digi for 15 minutes and then put it back in it works.

All of the DIGIs are using defaults except as noted:


More in-depth debugging will be needed. I recommend contacting Digi Tech. Support regarding this issue:

Direct: 952 912 3456
Email: tech.support@digi.com
Eservice Support: http://mydigi.force.com/customers

I did contact them but they would not help me beyond the DIGI itself. I need to know what could cause anything like this problem.